In the telecommunications industry connectors are commonly used which are designed according to certain mechanical and electrical standards. A well known electrical connector is the RJ 45 connector, which comprises a RJ 45 modular jack and a RJ 45 modular plug. A RJ 45 jack comprises generally eight contact elements or receptacle terminals which are located side by side within in a dielectric housing. In particular, RJ 45 jacks are used for high frequency transmission so that cross talk occurs between adjacent receptacle terminals. It has become to a major challenge to design connectors adapted to transmit high frequency data which lead to a reduced interference between adjacent receptacle terminals.
U.S. Pat. No. 6,840,779 B2 discloses a printed circuit board which is mounted within a modular jack. The printed circuit board comprises only a single compensation stage which includes capacitors disposed between the front side of the printed circuit board and the contact elements.
In order to reduce interference caused within a modular jack U.S. Pat. No. 6,840,779 B2 discloses a female connector mounted onto a base printed circuit board. A printed circuit board is mounted within the female connector. The compensation printed circuit board carries decoupling capacitors forming a single cross talk compensation stage which are connected to respective contact elements mounted on the printed circuit board. Each contact element on the compensation printed circuit board comprises a first leg ending in a free end. The first leg is connected to a second leg by a curved portion. The second leg is soldered to the compensation printed circuit board. which, in turn is electrically contacted to the base printed circuit board. The contact elements have a short electrical length in order to reduce the rise of cross talk within the modular jack. However, the prior art design does not have enough elastic deflection performance to compensate huge dimensional tolerances of a modular plug since the second leg of the contact elements is soldered at least over a portion of its length onto the compensation printed circuit board. Therefore, a frequent coupling and decoupling of the modular jack with the respective plug leads to a permanent deformation of the contact elements.
The single compensation stage of the known female connector is not able to sufficiently reduce cross talk so that an additional compensation circuit is arranged outside the female connector, i.e. on a base printed circuit board which the modular jack is mounted on.
Electrical signal transmission systems are disclosed in U.S. Pat. No. 5,310,363 which use specific conductor crossing techniques to reduce cross talk induced within a modular jack. A first system is described which comprises a printed circuit board which a modular jack is mounted on. Conductors running parallel and adjacent on the circuit board are crossed respectively to reduce cross talk between the respective conductors. According to a further known connector apparatus, a conductor array is mounted within a modular jack. Predetermined conductors of the conductor array are crossed to reduce cross talk introduced between them.
U.S. Pat. No. 5,997,358 discloses an electrical connector system which comprises a jack mounted on a printed wiring board. The printed wiring board includes two pairs of metallic conductors which comprise first and second compensating stages by crossing the metallic conductors of the first pair twice to cancel offending cross talk. U.S. Pat. No. 5,997,358 further discloses a communication jack assembly which comprises a multi-layer printing wiring board. In particular, the wiring board comprises eight layers of wiring paths. Each of the layers comprises metallic paths to provide three stages of compensating cross talk between respective wire pairs. The jack assembly further comprises a jack frame that is dimensioned to receive a modular plug in its front end and a rear opening that is dimensioned to receive the forward edge of the wiring board including jack wires.
In order to introduce multiple stages of compensating cross talk U.S. Pat. No. 5,997,358 further discloses to combine cross over technology with discrete component technology.
Moreover an electrical connector is disclosed which comprises time-delayed cross talk compensation. This is achieved by a conductor array which includes conductor leads which cross over each other in two locations in order to cancel cross talk.
It is an object of the present invention to provide a robust receptacle terminal for use within a modular jack which meet the mechanical requirements of an RJ 45 jack terminal.
It is a further object of the present invention to provide a compact modular jack with improved cross talk compensation performance in connection with robust receptacle terminals which normally increase cross talk between them.